Cell growth on pore-graded biomimetic TiO2 bone scaffolds

In order to prevent soft tissue down-growth into osseous defect areas, membranes are used when placing bone graft materials. These membranes still show shortcomings in their performance and applications. In the current study, we choose an approach to integrate micro-porous surface structures into a macro-porous scaffold. Low porous surfaces were fabricated by dip-coatings. Four different material compositions (titanium dioxide, polycaprolactone, polycaprolactone/water, polycaprolactone/β-tricalcium phosphate) were characterised in terms of their appearance, architecture, topographical features and cell response. Titanium dioxide surfaces exhibited rougher and more complex textures, resulting in the highest number of osteosarcoma cells and distinct morphologies in terms of cell spreading. Polycaprolactone-based surfaces showed a smoother topography and enhanced microporosity, but the effect on secretion of the bone markers sclerostin and interleukin-6 from human osteoblasts was lower compared to secretion from cells cultured on titanium dioxide. β-Tricalcium phosphate modification of polycaprolactone did not show any significant improvement regarding cell-material interaction. Nevertheless, surfaces show potential in the mechanical blockage of epithelial and soft tissue cells and may still permit sufficient nutrient transport.